Answer
No
Work Step by Step
Our aim is to determine that whether the given ordered pair is a solution or not. In order to find this we will plug the given values of $x$ and $y$ , respectively.
Plug $x=2,y=-1,z=3$ in the given ordered pair of equations.
First equation: $x+y+z=4$
$2-1+3=4$
Thus, $4=4$
Second equation: $x-2y-z=1$
$2-2(-1)-(3)=1$
Thus, $1=1$
Third equation: $2x-y-z=-1$
$2(2)+1-3=-1=1$ Thus, $2 \neq -1$
Hence, it is not a solution.
